Police said the gunman, a former employee identified as Dr. Henry Bello, opened fire inside Bronx Lebanon Hospital in the early afternoon.
Seven people were shot, one fatally, while others were injured fleeing the gunfire. Authorities say Bello died of a self-inflicted gunshot wound after apparently trying and failing to set himself on fire.
RELATED: What we know about the suspected gunman in hospital shooting
According to a law enforcement official, the shooter was wearing a lab coat and had the rifle concealed inside it.
Doctors reportedly refused to evacuate and insisted on treated the wounded right inside the hospital, and many other stories of heroism emerged from the tragedy.
One man, Eric Fisher, described the situation inside the hospital as he was locked in a bathroom with his wife, mother-in-law and newborn son.
The newborn, Ethan Reese Fisher, was in an incubator in the bathroom.
The parents had come in for a routine checkup with a pediatrician when the shooting unfolded.
Watch our interviews with witnesses and bystanders in the video players below: